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An early predominant manufacturer in the United States, Spencer Heath's American Propeller and Manufacturing Company was first to use machines for mass production of aircraft propellers. Under the Paragon trademark, these were widely used in World War I. Like most propellers of that era, construction was a wood laminate because of light weight, strength, fabrication ease, and resistance to fatigue in a vibrating and flexing environment.

Heath believed this artifact to be the first three-bladed airplane propeller, and noted that: "Three-bladed Paragons have nearly always given better results than two-bladed propellers of any type." First made in 1909, three-bladed Heath propellers served on Navy and Army Signal Corps aircraft.

Heath's rationale was: "Where the power is large or the propeller speed is low the propeller must of necessity have very high pitch in relation to diameter. In such cases the three-bladed propeller should be preferred in order to use a lower pitch without increasing the diameter."

Display Status

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.

Object Details
Date 1914-1939 Country of Origin United States of America Type PROPULSION-Propellers & Impellers Manufacturer American Propeller and Manufacturing Company
Designer Spencer Heath
Physical Description Type: Three-Blade, Fixed-Pitch, Wood Diameter: 215.9 cm (85 in.) Chord: 20.3 cm (8 in.) Engine Application: n/a Overall: Spruce wood Propeller: laminated wood Dimensions Rotor/Propeller: 213.4 x 20.3 x 12.7 x 6.4cm (84 x 8 x 5 x 2 1/2 in.)
Other (Blade Width, 29 in. From Center): 20.3cm (8 in.)
Materials Wood
Varnish
Adhesive
Inventory Number A19300036000 Credit Line Gift of American Propeller & Manufacturing Co. Data Source National Air and Space Museum Restrictions & Rights Usage conditions apply
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